The film was later developed, and it wasn't until one of party members was viewing the photos that it was noticed that the first (non-flash) photo showed a somewhat blurry extra head! (In the sequence above, the second (flash) photo is actually shown first for the sake of comparison.) No one recognized the ghostly woman, and they could not imagine how her image appeared in the picture. Besides being a bit out of focus, the woman's head is also too large compared to the other vacationers, unless she is sitting closer to the camera, which would put her in the middle of the table.
The photo was examined by the Royal Photographic Society, the photographic department of Leicester University, and the Society for Psychical Research, all of which ruled out a double exposure as the cause.